Useless Network Ever - MTN

My iMessage and FaceTime account was signed out for whatever reason, I called Apple support for activation and they said they need my mobile operator to send an sms for activation. For almost a week now MTN SA has been sending me from pillar to post and nobody seems to know how this should be done, i was asked to update latest ios, i did that and it didn’t help. I was asked to buy airtime for this international sms, i did that and didn’t help. And now they are saying they are unable to increase my credit limit so that this sms can be sent. MTN is just a useless and I want to end my service immediately, mxm